1 /* 2 * Copyright (C) 2010 Google Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of 14 * its contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY 18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY 21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #ifndef ReverbAccumulationBuffer_h 30 #define ReverbAccumulationBuffer_h 31 32 #include "AudioArray.h" 33 34 namespace WebCore { 35 36 // ReverbAccumulationBuffer is a circular delay buffer with one client reading from it and multiple clients 37 // writing/accumulating to it at different delay offsets from the read position. The read operation will zero the memory 38 // just read from the buffer, so it will be ready for accumulation the next time around. 39 class ReverbAccumulationBuffer { 40 public: 41 ReverbAccumulationBuffer(size_t length); 42 43 // This will read from, then clear-out numberOfFrames 44 void readAndClear(float* destination, size_t numberOfFrames); 45 46 // Each ReverbConvolverStage will accumulate its output at the appropriate delay from the read position. 47 // We need to pass in and update readIndex here, since each ReverbConvolverStage may be running in 48 // a different thread than the realtime thread calling ReadAndClear() and maintaining m_readIndex 49 // Returns the writeIndex where the accumulation took place 50 int accumulate(float* source, size_t numberOfFrames, int* readIndex, size_t delayFrames); 51 52 size_t readIndex() const { return m_readIndex; } 53 void updateReadIndex(int* readIndex, size_t numberOfFrames) const; 54 55 size_t readTimeFrame() const { return m_readTimeFrame; } 56 57 void reset(); 58 59 private: 60 AudioFloatArray m_buffer; 61 size_t m_readIndex; 62 size_t m_readTimeFrame; // for debugging (frame on continuous timeline) 63 }; 64 65 } // namespace WebCore 66 67 #endif // ReverbAccumulationBuffer_h 68
